Artificial hand



F. C. BECK.

ARTIFICIAL HAND.

APPLICATION FILED APR-16, 1918.

1,347,004. Patented July 20, 1920.

Fig.1.

2 SHEETSSHEET I.

Patented July 20, 1920.

2 SHEET SSHEET 2.

FCBecR hand after FRIEDRICH CONRAD BECK, 0F SEUZACH, NEAR 1V INTERTHUR, SWITZERLAND.

ARTIFICIAL HAN D.

1,3raoo4.

Application filed April 16,

To all whom it may concern:

Be it known that I, FRInnRIoH CONRAD BECK, a citizen of the Republic of Switzerland, residing at Seuzach, near lVinterthur, in the Canton of Zurich, Republic of Switzerland, have invented certain new and useful Improvements in Artificial Hands; and I do hereby declare the following to be a full, clear, and exact description ofthe invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters of reference marked thereon, which form a part of this specification.

The improved artificial hand according to the present invention is designed so that an effective grasping action is effected and comprises grasping members that are adapted to be actuated by cords operated in any known way by reason of their con nection with the natural arm left to the wearer.

The invention is clearly illustrated in the accompanying drawings in which:

Figure 1 shows the inside of the right the palm portion has been removed, and Fig. 2 is a detail view of the power-intensifying mechanism.

Fig. 3 is a side view of the artificial hand and of an artificial arm showing the connection of the hand with two stump muscles.

Figs. 4: and 5 are enlarged fragmentary details of the power-intensifying mechanism.

Referring first to Figs. 1 and 2, 1 is the back of the artificial right hand, the inside only of this back being visible. On the inside of the said back there are mounted two bearings 2 in which is fixed a stationary axle 3. On this axle 3 are mounted loose five cord pulleys 4:, 5, 6, 7 and 8. These pulleys are freely rotatable independently of one another but are unable to move axially. To each pulley 1-8 there is attached the end of a wire cord 9, 10, 11, 12 and 13. Of these wire cords, four, namely 912, are led from the top of the pulleys and pass over guide pulleys 14 down to the guide pulleys 16 located on the inner finger sections 15, and thence to the points of attachment 17 on the outside of the end finger sections 18. The fifth wire cord 13 runs from the lower side of the pulley 8 and passes over a guide pulley 19 Specification of Letters Patent.

Patented July 20, 1920.

1918. Serial No. 228,883.

to a point of attachment 20 on the thumb. The wire cords 913 are led past the finger joints 21, 22, and the thumb joint 21 respectively; they serve to close the hand or to enable it to grasp articles. To each cord pulley t8 there is attached one end of a spring 23, the other end of which is fixed to the axle 3. The springs 23 are coiled in such a manner that they are stressed when the pulleys 1-8 are rotated in the direction of the arrow y (Fig. 2).

The periphery of each cord pulley 4-8 is formed with ratchet teeth 24 engaged by a pawl bar This bar is normally disengaged from the ratchet teeth of the cord pulleys 1S, so that the latter are free to rotate in the direction of the arrow 3 The ends of the in slots 26 in extensions 27 of the bearings 2. On the right hand bearing 27 there is pivoted a lever 28 of long leverage which is movably jointed to the pawl bar 25 and upon whose end there acts a wire cord 30 passing over a pulley 29. The cord 30 is connected by means of an ivory bar to one of the two muscles (preferably a stump muscle which has been previously adapted to serve as a source of power). A wire cord 31 coming from the second muscle branches off into five branches 32, 33, 34, 35 and 36, of which the branches pass behind the finger joints 21, 22 to the points of attachment 17 on the fingers, while the branch 36 passes behind the thumb joints 37, 21 to the point of attachment 2O on the thumb.

When the first mentioned muscle acts to pull the wire cord 31, that is to say, the branch cores 3236, the fingers and the thumb are extended so as to open the hand completely, and simultaneously the springs 23 are stressed by the wire cords. As the V pawl bar 25 is normally not in engagement with the pulleys t-S, it can have a suitable rotation. As soon the article is within the range of the fingers this pull ceases, and then the stressed springs 23 effect a closing of the fingers and of the thumb. After this light grasping of the article which is also adapted to the shape of the article, the last mentioned muscle pulling the wire cord 30, causes by means of the lever 28 the pawl bar 25 to be pressed with force intensified by the leverage against the teeth 24 of the pulleys 4-8 (Figs. 2 and 4) and by this means with a further but small rotation of the said pawl bar 25 are guided connection attached to that mechanism spr ngs act ng pulleys the fingers as well as the thumb are pressed tightly against the article being" grasped seas to securely grip it.

The improved artificial hand may also be constructed in the form of what is known as a working hook. In order to produce abetter grasping action, the palm of the handis preferably provided with a pad whose thickness may vary w th the object in view. Moreover, the, ent re transmitt ng mechanism may be arranged abundant padding. instead of two muscles 'onlyo nemuscle may be utilized for operating the improved artificial hand, by prol pulleys, r'aekls a power-intensifyinglever with apawl bar as above described.

hatldlaiin isg. J p, H I

1. In an artificial hand, the eombiiiation with joined fingers thereof, of'a serie s of pawls and ratchets located centrally of the artificial hand, connectionsattached to said fingers and "said pawls and ratehets, and a tensile eonneetion attached 'to said pawls and ratchets, whereby patient by energizing said tensileIe nnecti n,is able, by operating sa d pawls and ratchets to cause said fingers to hold the grasped'ai'ticle with an optionalgripping 1 )ressure that is independent of the size or shapeof tl'lQdLltlClO to beheld. n l

2. In an artificial hand the c'oinbinatio'n with joined fingers thereof, of a te'nsile con nection ai m11e1t eaai fingers and to a source offpoweiyla mechanism including a series of pawls and ratchets located in the artificial hand, a connection attached to said fingersa nd to saidmec lia nisin, and a tensile wherehy"thel patient by energizing the first herein men loned te sile connection lscable to bend the artificial fingers into" a gr asp that is nearer to orvinside the 'wr st {or the purpose of providing more "pawl bar each engaging the ratchet teeth on eac'hiattached at one end be wound on and'off each'ot saldpulleys,

{against the: article held by the artificial hand, (I. V I v M V A. In "an artificl'al h'and,"t'l1e comblnati'on pawl liar each engaging theratc het teeth on each attached:

1 aid pawl bar, and e y to the other end of said'lever, whereof on thesaid pulleys more or less closely conformed to the contour f. theart to beheld, a i fih n yv ne ing the second herein-mentioned tensile connection isable, by operating said mechanism to cause said'fingers to hold the grasped article with an optional gripping pressure that is independent of'the size or shape of the article to be held.

3. In an artificial hand, the combination with jointed fingers thereot o'f an equal number of pulleys "rotatable freely and in- ]clependently of oneanotl'ier, common axle for sameimounted inthe artificial hand, a

diigof ratchet'teeth on eachpulley, a com mon'pawl b ar a"plurality of'p'awls'o n said 4., t., its respective pulley, a plurallty of cords to, and a;d'apted to andattacliedlat its other end to a finger of th arnficm hand, and'power-transmitting means for operating said common pawl bar, whereby on saidbar being operated to pull said cords e xtra tight, the attached finger will be pressed w th extra pressure ith jointed fingers fth 'r' a. (if an equal h' 'imber of'pulleys mantle fre el'y and independently of one' another, a common axle for same mounted in the artificial hand, a ring of ratchet teeth on eachpulle'y, a common pawlbar, a] plurality ofipawls on said its respective pulley, a plurality of cords .1: 5 1

at one end to, andadapted to be wound Qll i lijnfl off each said ull eys, and

attached at ts other end to la linger of the artificial han'd ia lever pivoted at one end to a common cord attache-d s 'cb mon 0'0 llw lie fil l di h Cards 'a're pulled with'fintehsified force and thereby the fingers are pressed with intensified p're ssureagainst the grasped article.

testimony "the-256i; lhavesigned my name this speeification intlie resence cl 7 two subscribingwitnesses. j

'FRIEDRICH CONRAD BECK. Witnesses:

Hiiii rAriN Huiainz, 'Tniroe 

